where \(\mathbb {E}\big \lbrace |\text{v}_{k_m}|^2\big \rbrace =a_k\big (\rho \epsilon _kc_k+\rho N+\epsilon _k N+N\big )\) can be easily obtained, \(\mathbb {E}\big \lbrace |\text{v}_{k_m}|^4\big \rbrace \)  was derived in [1]} and \(\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m})(\text{d}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \)  can be expressed as
\(\begin{split}&\hspace{5.0pt}\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m})(\text{d}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \\=&\hspace{5.0pt}a_k\xi _k\Big (\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m}^1)(\widetilde{\text{d}}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \hspace{-2.84544pt}+\hspace{-2.84544pt}\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m}^2)(\widetilde{\text{d}}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \\&\hspace{5.0pt}+\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m}^3)(\widetilde{\text{d}}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \hspace{-2.84544pt}+\hspace{-2.84544pt}\mathbb {E}\Big \lbrace \big (\text{Re}\big \lbrace (\text{v}_{k_m}^4)(\widetilde{\text{d}}_{k_m})^*\big \rbrace \big )^2\Big \rbrace \Big ).\end{split}\) 
